Packing.



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JMES IQPAXTON, OMAHA, NEBRAS.

Specification of Letters Patent.

Application filed May 29, 1913. Serial No. 770,670.

To all whom t may concern Be it known that T, JAMES L. PAx'roN, a citizen of the United States, residing at Omaha, in the county of Douglas and State of Nebraska, have invented certain new and useful Tmprovements in Packing; and I do hereby declare the following to be a full, clear, and exact description ofthe invention, such as will enable others skilled inthe art to which itl appertains to make and use the same.-

This invention relates to improvements in v metallic packing of the type adapted for effecting close joints between movingparts, and the objects in view is the improvement of the `specific type of packing set forth in U. S. Letters PatentNo. 647 ,313, granted to Thomas W. Mitchell, under date of April 1o, 1900.

In the accompanying drawing, Figure 1 is a view in elevation of a packing embodying the features of the invention, the piston being illustrated in section.` Fig. 2 is a central cross section therethrough.

While the structure set forth in the abovenamed patent, have proved exceptionally etlicient, some difficulty has been experienced from the tendency of the springs to creep longitudinally until they wedge in between the rocking ends of the packing segmentsA and the retainer ring, which occurs usually after the segments have become somewhat worn. Obviously, the end of a spring wedged between the rocking end of one pf the segments and the retaining ring will interfere with the rocking movement and thus. prevent the segment from maintaining an intimate contact with the piston.

The present invention is designed to overcome this difficulty and effectively attains this object through the embodiment illus- -trated in the accompanying drawing in which l, 1 indicate the segments of the packing ring, said ring surrounding the piston 2. Each segment l'has each end beveled,Y

one end of one segment overlapping the contiguous end of the other segment, the opposite end of the first segment underlapping the oppositeend of the second segment. yThe bevel of the ends of the segments 1 is inci- I dent to the curvature of said segments so that said ends are relatively flatwiththe Hat faces extending substantially taugentially with respect to the inner curvature of the segments and to the vsurface of the.

piston 2, the planes of said flat ends being vspring creeps longitudinally,

parallel. Thus the segments are adapted as the material thereof wears away to be moved radially toward the piston and thus maintain an'intimate contact therewith. To insure such radial movement, as well as to provide for a constant pressure maintaining the segments in contact with the surface of the piston 2, each segment 1 is engaged by a plate spring 3. The springs and segments are surrounded by the retainer ringv 4, and each segment is formed with a longitudinal peripheral notch 5,"which accommodates the respective spring 3 and at the ends of which the respective segment is formed with shoulders 6, 6, which are suiiiciently'abrupt to insure contact therewith by the respective end of the corresponding spring 3, when the so that the spring cannot possibly escape and wedge itself between the respective end portion of the segment and the ring 4. To insure this result, each spring 3 has its end portions bent inwardly, preferably centrally thereof, is formed with i a radially, inwardly extending projection 8,

which is preferably formed of the material of the spring stamped or punched toy prov to move outwardly,iand a resultant springl pressure at the projection 8 being exerted radially inwardly.

c Each end portion of each segment 1 has its outer surface rounded, as indicated at 9, and the rounded portion extends to the respective shoulder 6, so-that each of the segments is free to rock' when necessary for effecting the requisite inward travel, and liabil'jtyy of interferenceI with such rocking by the springs 3 is entirely obviated. It will thus be noted that the two segmental sections l constantly coperate to form a I very intimate joint about the piston, and

that the single point contactv8 of each spring both obviates undue friction and leaves the respective section l free for such movement as variations in wear may necessitate.

What I claim is l. lin a comprising arcuate sectlons, each having a bevel at one end with the inclined face of the bevel exposed outward and a corresponding bevel at the other end with the inclined Patented Apr. 25, 1916.,

as at 7, 7. Each spring 3,'

piston packing, a packing ring` face of the bevel exposed inward, each beveled surface lying substantially at a tangent to the circle described by the inner surface of the ring, and the inwardly exposed inclined face of each sectionoverlying the outwardly exposed inclined face of the other,

` a spring for each section pressing the middle portion inward, and means for preventing movement of each spring to a position pressing an end portion of its respective section.

2. In a piston packing, a packing ring i comprising arcuate sect1ons,feach having a bevel at one end with the'inclined face of the bevel exposed outward anda corresponding bevel at the other end with the inclined face of the bevel exposed' inward, each p beveled surface lying substantially at a tangent to the circle described by the inner surface of the ring, land the inwardly exposed inclined face of'each section overlying the outwardly exposed inclined face of the other,

anda spring for each section pressing the v middle portion inward, each section having a shouldered portion adjacent each end of 'the spring for confining the spring against l substantial displacement.

. 3. In a pistonpacking, a` packing ring comprising arcuate sections,l eachhaving a face of each section overlying the outwardly exposed inclined face of the other, and a plate spring lfor each section pressing the middle portion inward, each spring having at its middle portion a projection extending toward and engaging the respective section, and each section having extensions at'its end portions disposed to interrupt longitudinal travel of the spring.

il. Ina piston packing, a packing ring section adapted to cooperate with a like section and having a bevel at one end with the inclined face of the bevel exposed outward and a corresponding bevel at the other end'with the inclined face of the bevel exposed inward, each bevel surface lying substantially at a tangent tothe circle whose arc is described by the inner surface of the section, and the inwardly exposed inclined face of the section being adapted `to overlie the outwardly exposed inclined face of a coperatingv section and to have its outwardly exposed inclined face overlapped by the inwardly exposed inclined face of a coperating section, the section being formed with terminal shoulders and a peripheral recess between the shoulders adapted to accommodate a spring confined against circumferential travel by the shoulders.'

In testimony whereof I affix my signature in presence yof two witnesses.

JAMES L. PAXTON.

' Witnesses l:` CHAs. L. DUNDEY,

. I RUTH FARRELL. 

